Rainline Garden

When to plant kohlrabi in Walla Walla, WA

Plant kohlrabi in the garden in Walla Walla Apr 1 – May 13, either as seeds or as young plants started indoors Feb 18 – Mar 4. For a fall harvest, plant again Aug 13–27.

Easy Plant seeds or young plants

Why these dates

Walla Walla's typical last spring frost is March 27. In the Columbia Basin and low eastern valleys, the soil is usually ready for kohlrabi around April 1.

Columbia Basin and low eastern valleys. Hot, dry summers and quick spring warm-up. Warm crops go in earlier than west of the Cascades, and irrigation matters more than rain.

Difficulty
Easy
Sun
Full sun
Spacing
Thin to 6 inches apart
Planting depth
¼ to ½ inch deep
Frost
Handles light frost
First harvest
About 55 days after planting

Step by step

  1. Start seeds indoors Feb 18 – Mar 4 in trays or small pots under a grow light or in your sunniest window. Or skip this step and buy young plants (starts) at a garden center.
  2. Harden off the young plants: about a week before planting, set them outside for a few hours a day, a little longer each day.
  3. Plant them in the garden Apr 1 – May 13, Thin to 6 inches apart. If you plant seeds instead, sow them ¼ to ½ inch deep.
  4. Water deeply once or twice a week rather than a little every day, and mulch once the soil is warm.
  5. Plant again Aug 13–27 for a fall harvest.
  6. Harvest: Cut bulbs at 2 to 3 inches across. Peel off the tough skin and eat raw or cooked.

Varieties that do well here

  • Kolibri (purple)
  • Winner
  • Kossak (large, stores well)

Watch out for

Cabbage worms chew the leaves. Insect netting keeps the white moths from laying eggs.

Pick when the bulb is about tennis-ball size; bigger ones turn woody.

Common questions

When is the last frost in Walla Walla, WA?

Typically March 27. In 9 years out of 10, frost is over by April 22. These are 1991–2020 NOAA climate normals for Walla Walla Regional Airport.

Is it too late to plant kohlrabi in Walla Walla?

The spring planting window runs through May 13. If you miss it, plant again for fall from August 13 to August 27.

When should I start kohlrabi from seed indoors in Walla Walla?

February 18 to March 4, which is 6 to 4 weeks before the April 1 planting date. Or buy young plants at a garden center instead.

Also plant in Walla Walla around the same time

Planting dates for kohlrabi in nearby areas

Full planting calendar for Walla Walla · Kohlrabi in every city